Air content--via the oxygen component of air--in a liquid is a quantity that is of interest to the canning industry in general and the beverage industry in particular. This invention utilizes a polarographic probe to make an electronic measurement of the oxygen component in the gaseous state. Although it might be theoretically possible to make a measurement in the liquid, such a measurement is both difficult mechanically and difficult to analyze. The interpretation of the data because of solubility problems which are a function of additives (wanted and unwanted) would be very complex and troublesome. Temperature and pressure variations are also a problem. Air is primarily nitrogen and oxygen in approximately a 4 to 1 ratio (80% nitrogen, 20% oxygen). There is no direct electronic measurement for nitrogen but air content can be calculated by measuring the oxygen component. Also this measurement can separate the amount of air in the head space of a drink (that space that is not occupied by liquid) from the air in the beverage.